Charles JefferiesRazer Core X ChromaRazer's top-shelf eGPU, the Core X Chroma, has customizable RGB lighting and a practical port hub. Like other Thunderbolt 3 eGPUs we've tested, however, expect a major dip in graphics-card performance versus the same card in a full desktop PC.

Card performance is constrained versus on a desktop, in our testing. Chassis lighting not programmable on Macs.

Bottom Line

Razer's top-shelf eGPU, the Core X Chroma, has customizable RGB lighting and a practical port hub. Like other Thunderbolt 3 eGPUs we've tested, however, expect a major dip in graphics-card performance versus the same card in a full desktop PC.

Razer's Core X Chroma ($399) is the company's flagship external graphics-card solution (eGPU). The concept of an eGPU, if you haven't seen one before, is simple: Install a graphics card of your choice in the eGPU box, then connect it to your Thunderbolt 3-equipped Mac or Windows 10 computer (typically, a laptop) for a serious boost in gaming or content-creation performance. Our testing showed the Core X Chroma has the same technical limitations we found with other Thunderbolt 3 eGPUs, but it overall works as intended, providing our Windows 10 PCs with enough power to play today's games. The Core X Chroma adds user-customizable RGB lighting and a port hub (Ethernet, plus four USB ports) over Razer's base eGPU model, the Razer Core X, making it a versatile and practical choice for an eGPU solution. Combined with an excellent-quality case and its good looks, this is the eGPU to beat, but be sure to read the full review to understand what it can (and can't) do.

Bringing Chroma-Ticity to eGPUs

It's not a thin cover, either; the enclosure weighs 14.3 pounds without a graphics card. Razer's silver-outlined logo adorns the cooling grate on the right side...

Meanwhile, the graphics card you install will be visible through the grate on the left...

Additional passive ventilation comes from a grate on the rear. The underside of the unit is almost entirely coated in rubber to keep it from sliding around.

The regular Core X enclosure has the same 9.1-by-6.6-by-14.7-inch (HWD) dimensions and overall design, but it lacks the customizable RGB lighting effects found on the Core X Chroma. The pretty lights are managed through Razer's Synapse software, which I was automatically prompted to download after connecting the Core X Chroma to my computer.

Synapse allows you to change the brightness and when (or if) the lighting effects turn off. You can choose from preset lighting effects on this screen, or choose the Advanced Effects option to open Chroma Studio...

I thought the Core X Chroma had one or two lighting zones the first time I powered it on, but I was wrong: It has a whopping 16 zones.

The largest one illuminates the graphics card through the left-side grate, while the other 15 make up the light bar under the front panel in a piano-like fashion...

You can create an unlimited number of profiles. The Synapse software and Chroma Studio can be used to manage your other Razer devices, too. It's unfortunate that the Chroma lighting isn't supported on Macs; attached to a Mac, the chassis still lights up, but only in its Spectrum color-cycling mode. For changeable and custom effects, you'll need to use a Windows 10 PC and the Synapse software.

The Core X Chroma doubles as a port hub and in essence a dock. Along the backside, you'll find four USB 3.1 Type-A ports and a gigabit Ethernet jack. You can undock a laptop from an external monitor, multiple peripherals, and a wired network connection via one (Thunderbolt 3) cable.

The Thunderbolt 3 connector is just below them. Don't forget, you'll also have any video connectors on whichever graphics card you install.

The installation of a graphics card in the Core X Chroma is easier than it is in a typical desktop. No need to remove the enclosure or undo any screws; instead, just pull the handle at the rear of the unit to slide out the entire interior on a smooth-gliding sled.

The logic board, the power supply, and the cooling fan are mounted on it. Install your graphics card in the PCI Express slot, connect the power cables, and close it up. I like the fact there's no lockdown lever for the slot, making the uninstallation of a graphics card less complicated. The handle acts as its own safety feature, too, as it won't fully open (and thus won't allow the sled to come out) if the wall power cable is connected. The power supply also has a physical on/off switch that was missing on the prior Razer Core V2 eGPU.

The inside of the Core X Chroma is big enough to house just about any two- or three-slot wide, full-length desktop graphics card. It supplies up to 500 watts to the graphics card via two 6+2 pin connectors, and 100 watts through the Thunderbolt 3 connection to act as a power source for laptops that support charging via Thunderbolt 3. (The latter is an improvement over the Core V2, which supplied only up to 65 watts.) The included Thunderbolt 3 cable is just under 20 inches (a half-meter) long; Razer sells a two-meter cable if you want more freedom.

The Core X Chroma has ample air circulation from the grates on both sides and the rear of the chassis, plus active exhaust from an internal 120mm fan and the fan in the power supply. The fins on the front panel of the enclosure are just for show. It's a solid piece, and no air comes through this panel. Even so, I noticed no significant fan noise coming from the Core X Chroma while running benchmark tests. Its internal fans are large and don't need to spin fast.

Given the open design of the enclosure, however, it pays to use a graphics card that's known for being quiet. This is especially true if you don't get the extended Thunderbolt 3 cable, as the Core X Chroma will be sitting about two feet away from your computer, at most.

Install and Setup: Easy Enough

I tested the Core X Chroma with two Windows 10-based PCs. Sorry, Mac fans; I opted for these two machines to examine the differences in performance with a couple of different video cards in two different eGPU use modes, which I'll get into in a moment. A MacBook laptop would not have generated useful comparison numbers, due to the lack of support for common game software between Windows and macOS.

The installation in both cases was as simple as plugging in the Thunderbolt 3 cable. The fans on the graphics card immediately spun up to maximum speed, as they've done on other Thunderbolt 3 eGPUs I've tested, but they quieted down after I allowed the Core X Chroma to connect via an automatic pop-up from Intel's Thunderbolt 3 software. (The latter should be pre-installed on Thunderbolt 3-equipped PCs.)

Windows 10 then automatically downloaded and installed the graphics card driver for the Nvidia graphics card I installed. The process took about 10 minutes, after which the graphics card showed up in the Windows Device Manager like any other display adapter.

Running applications on an eGPU is something I discussed at length in my review of the OWC Mercury Helios FX 650 eGPU, one of the Core X Chroma's competitors. Regardless of the computer you're using, it should always be possible to run an application (such as a game) on the eGPU provided you're running it on a monitor that is directly connected to the video outputs on the back of the video card in the eGPU. The eGPU, however, won't power a monitor that is connected to one of the native (i.e., non-video-card) video-out connectors on your computer; the external display will continue to be powered by the computer's onboard graphics solution, assuming it has one. It's a technical limitation of Thunderbolt 3 eGPUs, not one specific to the Core X Chroma.

You'll also want to be careful when it comes to notebooks. One of the test computers I used, a Lenovo ThinkPad T490 business notebook, allowed the Core X Chroma to feed the GPU-accelerated video signal back to the laptop's built-in display. However, this won't be possible with every Thunderbolt 3-equipped notebook due to variances in Thunderbolt 3 implementations.

Furthermore, note that while Thunderbolt 3 is officially rated for up to 40Gbps of bandwidth, not all Thunderbolt 3-equipped computers will provide that. Some, for instance, will have a half-bandwidth (20Gbps) implementation because of how the PCI Express lanes in the computer communicate with the processor. There's a myriad of possible configurations out there, which is why eGPUs are hard to recommend without reservations. There are technical gotchas, and just no guarantee it's going to work the way you want (or as well as you might expect) in every situation.

Meet the Test Setups

I used two very different Windows 10-based computers for testing: an Intel NUC Kit NUC8i7HVK mini-desktop with an Intel Core i7-8809G processor chip, and the ThinkPad T490 laptop I mentioned, which uses a Core i7-8565U mobile chip. Both processors are quad-core, eight-thread parts, but the one in the Intel NUC is far more powerful and reflected in its higher thermal design power (TDP) rating. The ThinkPad, in contrast, will provide an interesting perspective into processor-related bottlenecks in the performance testing.

This card is the top-end card a gamer would reasonably use in an eGPU, made for playing games at 4K resolution, or very high frame rates at 1440p.

I also tested the eGPU on both client systems with a GeForce RTX 2060 Founders Edition card, a mid-level choice that is a more practical one for eGPU use, at least for gaming. (This will become obvious in the benchmarks.)

The Core X Chroma will be joined by the OWC Mercury Helios FX 650 in the charts below, in an effort to find out if one enclosure performs markedly better than the other. In addition, I also included results for each of these video cards, on the same tests, with the card installed in PC Labs' video-card test desktop. The idea there is to show how the graphics cards perform in a desktop environment with a full-power desktop CPU behind them (in this case, an Intel Core i7-8700K) as opposed to operating in an eGPU environment with CPU and bandwidth constraints.

Benchmarks, Part One: On an External Monitor

The benchmarks and games in this section were run on a monitor directly connected to a video output on the card inside the eGPU. The eGPU was connected, for the tests, to the Intel NUC and then upon completion to the Lenovo ThinkPad T490. My testing with the ThinkPad T490 showed there are performance differences between using the eGPU in this arrangement versus using "loopback" to the laptop's internal display. (I dedicate a section to that scenario later in this review.)

3DMark Time Spy

This is Futuremark's DirectX 12-enabled benchmark for predicting the performance of DirectX 12-enabled games. It uses major features of the API, including asynchronous compute, explicit multi-adapter, and multi-threading.

The eGPU setups are handily outperformed by the PC Labs desktop rig across the charts. Some of this is due to the latter's powerful Core i7-8700K processor, but not all; there's not quite as much of a difference between the RTX 2060 and the RTX 2080 Ti in the eGPU rigs (around 50 percent), whereas it's about 58 percent with the cards tested in the desktop.

What is clear: The eGPU setups are running into a bottleneck, but we haven't seen its full effect just yet. Meanwhile, the performance differences between the Core X Chroma and the Mercury Helios FX 650 are too small to say one performs noticeably better than the other.

Unigine Superposition

Another synthetic benchmark is Unigine's 2017 release, Superposition. This benchmark does incorporate ray tracing, but it's done in software, not hardware, and thus doesn't utilize the RT cores of the RTX 20 series in these charts.

This test shows the eGPU setups performing on par with the desktop, which might not seem logical, but it does make sense when you consider that this test can run simulations of 4K or even 8K workloads without such a display on hand. Also, the frame-per-second (fps) rates reached aren't high enough to saturate the available bandwidth on the Thunderbolt 3 connections. In that sense, it's not a super-realistic test for modern gaming, but it demonstrates an eGPU can compare with a desktop setup in isolated scenarios.

Rise of the Tomb Raider

The 2015 predecessor to Shadow of the Tomb Raider is still a solid gaming benchmark.

Now we're seeing the opposite of the Superposition results; the eGPU setups aren't within a country mile of the desktop setup. In fact, the RTX 2060 in the test desktop (mind you, a card that costs about $350) performs uncomfortably close to the $1,000-plus RTX 2080 Ti in the eGPUs.

Given that the eGPUs show only modest differences between the RTX 2060 and the RTX 2080 Ti, it's more than likely there's a bandwidth limitation related to the Thunderbolt 3 interface on these test computers. There continues to be no conclusive difference between the Core X Chroma and the Mercury Helios FX 650.

Far Cry 5

The fifth installment in the Far Cry series is based on DirectX 11, but still demanding.

This game shows a greater delta between the RTX 2060 and the RTX 2080 Ti in the eGPU setups, as it's more graphically demanding, and the processor is less of a bottleneck. Nonetheless, there are still significant bottlenecks related to the Thunderbolt 3 connection. The RTX 2080 Ti in the eGPUs, even when paired with the Intel NUC8i7HVK, is still slower than the RTX 2060 in the desktop setup.

Another trend that prevailed is that the processor performance matters. The slower processor in the ThinkPad T490 visibly throttled its performance next to the Intel NUC8i7HVK, albeit not to the degree that it couldn't play games.

Benchmarks, Part Two: Tested on Laptop Displays

The results you'll see in this section are only for the ThinkPad T490, because of the two test systems, this one is the only laptop. (The Intel NUC uses an external monitor.) These tests compare benchmark performance on its internal display versus using an external display directly connected to the eGPU.

3DMark Time Spy

These differences are good projections of the performance hit you'll see from using the eGPU to accelerate gaming on the internal display on this notebook...

While significant, it shouldn't deter you from gaming on the laptop's display. Note how the variation isn't as great with the less-powerful RTX 2060.

Unigine Superposition

As we saw in the last round of testing, Superposition shows little difference between the test scenarios...

The processor is no longer a factor since we're dealing with one computer, and the average fps is low enough that Thunderbolt 3 bandwidth likely wasn't a major factor, either.

Rise of the Tomb Raider & Far Cry 5

I had difficulty getting consistent results from the Rise of the Tomb Raider benchmark, so we'll put those aside. In Far Cry 5, running on the external display produced an 18 to 24 percent performance gain...

You'd be hard-pressed to notice the gain on the ThinkPad T490 I'm using to test, however. It has just a 60Hz display, and the average frame rate using the internal display in both games is right around that.

To that end, it hardly makes economic sense to invest in more than a midlevel card for eGPU usage, at least for gaming, if you'll just be looping the gameplay back to the laptop's internal display. After all, just about all laptops that don't have a dedicated GPU have a 60Hz screen.

A Standout Add-On, as eGPUs Come

The Core X Chroma worked as it was supposed to in our testing, transforming our test PCs into full-fledged gaming machines. It works with both Macs and PCs, and the graphics-card installation and overall setup is straightforward. It doesn't get any simpler, as far as eGPUs go.

That said, the Core X Chroma is still a relatively expensive proposition for adding graphics oomph to your Thunderbolt 3-equipped computer, as its list price doesn't include a graphics card. (There's a Core X non-Chroma model that doesn't have the port hub or RGB lighting, for $100 less.) In real-world gaming scenarios, the graphics cards we installed in the Core X Chroma performed much worse than they did in a traditional desktop setup. In addition, it didn't power the native video connectors on our test computers, requiring us to plug an external monitor directly into the card's connectors in the back of the Core X Chroma if we wanted to use it for gaming. Last, while it did power the internal screen of our ThinkPad T490 test laptop, there's no guarantee it can do that with every laptop. We had the same experience with the competing OWC Mercury Helios FX 650, so these aren't problems exclusive to Razer with this product; it's just the nature of Thunderbolt 3 eGPUs.

All told, though, Thunderbolt 3 eGPUs are a promising way to add graphics performance to Macs and PCs if you're set on keeping your whole computing world centered on a laptop you plug in to play at night, then take on the road in the morning. The Razer Core X Chroma is the most convincing option we've seen, incorporating customizable RGB lighting and a port hub into a stylish, high-quality enclosure that accepts almost any desktop graphics card. For added practicality, it can also supply up to 100 watts of power to laptops that support charging via Thunderbolt 3. If you can get past the technical limitations with Thunderbolt 3 eGPUs, the Core X Chroma is the one to beat.

Razer Core X Chroma

Bottom Line: Razer's top-shelf eGPU, the Core X Chroma, has customizable RGB lighting and a practical port hub. Like other Thunderbolt 3 eGPUs we've tested, however, expect a major dip in graphics-card performance versus the same card in a full desktop PC.

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About the Author

Charles Jefferies is a native of the Philadelphia area who has been reviewing laptops and related hardware since 2005. A graduate of Rochester Institute of Technology, he enjoys all aspects of consumer and business tech, especially PCs, tablets, and photography. He works professionally as an HR payroll consultant and when not working can be found o... See Full Bio

Razer Core X Chroma

Razer Core X Chroma

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